Buggy code:
public class StorageProxy implements StorageProxyMBean { private static Logger logger = Logger . getLogger ( StorageProxy . class ) ; private static TimedStatsDeque readStats = new TimedStatsDeque ( 60000 ) ; private static TimedStatsDeque rangeStats = new TimedStatsDeque ( 60000 ) ; private static TimedStatsDeque writeStats = new TimedStatsDeque ( 60000 ) ; private StorageProxy ( ) { } private static Comparator < String > keyComparator = new Comparator < String > ( ) { public int compare ( String o1 , String o2 ) { } } ; public static void insert ( final RowMutation rm ) { long startTime = System . currentTimeMillis ( ) ; try { List < InetAddress > naturalEndpoints = StorageService . instance ( ) . getNaturalEndpoints ( rm . key ( ) ) ; Map < InetAddress , InetAddress > endpointMap = StorageService . instance ( ) . getHintedEndpointMap ( rm . key ( ) , naturalEndpoints ) ; Message unhintedMessage = null ; for ( Map . Entry < InetAddress , InetAddress > entry : endpointMap . entrySet ( ) ) { InetAddress target = entry . getKey ( ) ; InetAddress hintedTarget = entry . getValue ( ) ; if ( target . equals ( hintedTarget ) ) { if ( target . equals ( FBUtilities . getLocalAddress ( ) ) ) { if ( StorageProxy . logger . isDebugEnabled ( ) ) StorageProxy . logger . debug ( ( "insert<seq2seq4repair_space>writing<seq2seq4repair_space>local<seq2seq4repair_space>key<seq2seq4repair_space>" + ( rm . key ( ) ) ) ) ; Runnable runnable = new Runnable ( ) { public void run ( ) { try { rm . apply ( ) ; } catch ( IOException e ) { throw new IOError ( e ) ; } } } ; StageManager . getStage ( mutationStage_ ) . execute ( runnable ) ; } else { if ( unhintedMessage == null ) unhintedMessage = rm . makeRowMutationMessage ( ) ; if ( StorageProxy . logger . isDebugEnabled ( ) ) StorageProxy . logger . debug ( ( ( ( ( ( "insert<seq2seq4repair_space>writing<seq2seq4repair_space>key<seq2seq4repair_space>" + ( rm . key ( ) ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>" ) + ( unhintedMessage . getMessageId ( ) ) ) + "@" ) + target ) ) ; MessagingService . instance ( ) . sendOneWay ( unhintedMessage , target ) ; } } else { Message hintedMessage = rm . makeRowMutationMessage ( ) ; hintedMessage . addHeader ( HINT , target . getAddress ( ) ) ; if ( StorageProxy . logger . isDebugEnabled ( ) ) <START_BUG> StorageProxy . logger . debug ( ( ( ( ( ( ( ( "insert<seq2seq4repair_space>writing<seq2seq4repair_space>key<seq2seq4repair_space>" + ( rm . key ( ) ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>" ) + ( unhintedMessage . getMessageId ( ) ) ) + "@" ) + hintedTarget ) + "<seq2seq4repair_space>for<seq2seq4repair_space>" ) + target ) ) ; <END_BUG> MessagingService . instance ( ) . sendOneWay ( hintedMessage , hintedTarget ) ; } } } catch ( IOException e ) { throw new RuntimeException ( ( "error<seq2seq4repair_space>inserting<seq2seq4repair_space>key<seq2seq4repair_space>" + ( rm . key ( ) ) ) , e ) ; } finally { StorageProxy . writeStats . add ( ( ( System . currentTimeMillis ( ) ) - startTime ) ) ; } } public static void insertBlocking ( final RowMutation rm , int consistency_level ) throws TimedOutException , UnavailableException { } private static int determineBlockFor ( int naturalTargets , int hintedTargets , int consistency_level ) { } private static List < Row > weakReadRemote ( List < ReadCommand > commands ) throws IOException , TimedOutException , UnavailableException { } public static List < Row > readProtocol ( List < ReadCommand > commands , int consistency_level ) throws IOException , TimedOutException , UnavailableException { } private static List < Row > strongRead ( List < ReadCommand > commands , int consistency_level ) throws IOException , TimedOutException , UnavailableException { } private static List < Row > weakReadLocal ( List < ReadCommand > commands ) { } static List < Pair < String , Collection < IColumn > > > getRangeSlice ( RangeSliceCommand command , int consistency_level ) throws IOException , TimedOutException , UnavailableException { } static List < String > getKeyRange ( RangeCommand command ) throws IOException , TimedOutException , UnavailableException { } public double getReadLatency ( ) { } public double getRangeLatency ( ) { } public double getWriteLatency ( ) { } public int getReadOperations ( ) { } public int getRangeOperations ( ) { } public int getWriteOperations ( ) { } static class weakReadLocalCallable implements Callable < Object > { private ReadCommand command ; weakReadLocalCallable ( ReadCommand command ) { } public Object call ( ) throws IOException { } } }

Fix:
StorageProxy . logger . debug ( ( ( ( ( ( ( ( "insert<seq2seq4repair_space>writing<seq2seq4repair_space>key<seq2seq4repair_space>" + ( rm . key ( ) ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>" ) + ( hintedMessage . getMessageId ( ) ) ) + "@" ) + hintedTarget ) + "<seq2seq4repair_space>for<seq2seq4repair_space>" ) + target ) ) ;